Stamps that have major, consistent, and unintentional deviation from the normal stamps are considered errors. Postage stamp errors are sometimes caused during stamp printing process. Error stamps do not show the intended appearance of the desired stamp design.
There are factors that cause postage stamp errors like wrong denominations, wrong or missing colors, misplaced or an inverted design element, missing parts of the stamp design, wrong stamp paper, wrong watermark, double impressions, and others.
Color error postal stamp occurs when stamp is printed with wrong color(s) or one or more color is missing. These color error postal stamps usually occur when one stage of a multi-run printing process is skipped. One example of this type of error is the stamp above featuring the national anthem of Uruguay. A gold color on the edge of the score of missing. Click this to compare with the error-free stamp. The error increased the value of the stamp 100x.